Pneumatic tire



M. J. c. ANDRE PNEU I0 TIRE led Ma 15. 1922 June 12, 1923.

Patented Jane l2, l23.

UNHTE stares intense rater torch.

* i I MARIE JOSEPH CAMILILE ANDRE, 0E PARIS, FRANCE.

PNEUMATIG TIRE.

Application filed March 13, 192? enial 230. 548,437.

To all whom it may concern: I

Be it known that I, MARIE JOSEPH CAMILLE Arman, citizen of the Republicof France, and resident of 165 Rue de Tolbiac, Paris, in the saidRepublic, engineer, have invented certain new and useful Improvements inPneumatic Tires; and I do hereby declare the following to be a full,clear, and exact description of the invention, such. as will enableothers skilled in the art to which it appertains to make anduse thesame, reference being had to the accompanyin drawings, and to letters orfigures of re erence marked thereon, which form a part of thisspecification.

' This invention relates to a ty e of tire in which an envelope isplaced tweenthe external cover and the air tube, so that a greaterthickness of rubber is interposed between the latter and the soil andprevents the tube from being pierced. Moreover, according to thisinvention, the whole tire is so designed that it is not likely to blowcult. The tire is cooled in running by a continuous circulation of airinside. The tire is economieal owing to the fact that the necessaryresistance is mainly afforded by the intermediate envelo e, andconsequently a comparatively smal quantity of fabric need be employed inthe construction of the external cover, which is that part of the tirewhich must be the most often replaced. A further. economy is realized bythe fact that the air tube has a diameter less than is usually the case.

The present improvement has been especially contrived with a view torealizing economy in the cost of the external cover witlioutsacrificingthe resistance of the tire, and of securing an eiiicient circulation ofair without making holes either in the tread or sides ofthe tire, thuspreventing every. ris of the inlet and outlet air openings becomingobstructed.

According to, one form of embodiment of theinvention the grooves at theexternal or eripheralv surface or tread portion of theintermediateenvelope are formed generally crosswise. -They communicatetogether, on each side of the tire, by means of a oove which extendscircumferentially an communicates with an opening or openings formedthrough the bead of the external cover and the folly rim of the wheel,thus permitting the air to circulate freely.

Flgure l of the drawing is a transverse section of a tire constructedaccording to this invention and shown in' position on the folly of awheel. Figure 2 is a plan view of part of the intermediate envelope,showing its cross grooves and the collecting grooves, and

Figure 3 is a view similar to Fig. 2 showing a modification in which thecross grooves are arranged diagonally.

Figure 4 is a transverse section of part of an external cover in whichthe hook shaped edges are replaced by ed es containing strengtheningcables, adapts for use on a detachable rim.

In the drawing a is the ordinary air tube,

Z; is the external cover, a the intermediate envelope, d the rim onwhich the tire is mounted.

The sides of the intermediate envelope are made or plies or layers ofcloth, three by preference, combined with rubber. the lower part of eachside a bead c is formed containing a core made of hard rubher or thelike, for the purpose of securin the intermediate envelope to theexterna cover 6, which latter is provided with corresponding circularrecesses. Having regard to cross-section as in Fig. 1, at the up or partof the internal cover a is secure a k crescent f of rubber, of the shapeshown,

entire surface of which are formed transverse ooves g, rounded bypreference, all of which open into a circular groove-'7, on each side ofthe tire the circular groove communicating with the atmosphere as willbe hereafter explained.

- The external cover fits closely on the intermediate envelope and issecured thereto by means of circular recesses receiving the beads e. Theexternal cover ma be fixed to the rim in any ordinary way, or example, bmeans of hook shaped edges 2' ente a tli e'turned over edges 7' of therim.

The sides of the external cover are by Near V preference made of fourplies or layers of cloth. At the tread and in the adjacent parts thereare only two plies of cloth, upon which is a thick layer of rubber.Projections and hollows may be formed on the tread in the usual mannerto avoid slip- In order that the two circular grooves h, h in which thecross grooves 9 open, may communicate with the atmosphere, aradialchannel is is formed, in the moulding process, either on the externalsurface of the intermediate envelope as shown or on 'the internalsurface of the external cover, on each side of the tire, which grooveextends from the circular groove h to a hole Z formed in the bead i ofthe external cover. and which communicates witha hole in the telly,continued by a small tube m.

When it isprefer'redto form the passage k on the intermediate envelope,as shown,-

then it is formed in. a band of rubber ta piereld at itsedges which iscemented on the 0 0t The radial passages 7c, holes Z, and tubes m existat a number of points of the circumference of the tire, in order tosecure a communication from the circular grooves k, to the atmosphere.It is obvious that such a communication with the exterior at oppositepoints in the tire secures an eflicient renewal of the air inside thelatter and thus prevents the tire from overheating and thereby avoidsblow-outs. Of course the number of air inlets and outlets and oicorresponding channels, may be varied as desired.

.A partition n formed of a small block of rubber is arranged in each ofthe cross grooves g in order to divide the current of air in view ofsecuring the proper issue or admission of air through the correspondingtubes m.

I claim:

A pneumatic tire comprising an external cover'having retaining beadsformed with apertures, an intermediate envelope mounted in the cover andhaving a thick tread formed with transverse ripher'al grooves whichcommunicate witli annular grooves formed in the sides of the tread, a1rpassages connectingthe annular grooves with the apertures in the cover,and yielding partitions centrally arranged in the transverse groovesoperable during the running of the a tire to cause an ingress and egressof air through the apertures.

In testimony that I claim the foregoing as my invention, 1 have signedmy name.

MAME aosrru tannin ANDRE,

